The invention relates to a method of designing a drilling pattern for excavating a rock cavern. A drilling pattern determines at least the locations and hole direction angles of drill holes in the coordinate system of the drilling pattern and the lengths of the drill holes for a round to be drilled at a tunnel face. In the method, a designer designs the drilling pattern with the aid of a drilling pattern design program. The object of the invention is described in more detail in the preamble of the first independent claim.
The invention also relates to a software product as claimed in the second independent claim, the execution of the software product in an designing computer generating actions required for designing the drilling pattern. Furthermore, the invention relates to a rock-drilling rig as claimed in the preamble of the third independent claim, the software product being executable in a control unit of the rock-drilling rig for achieving the actions required for designing the drilling pattern.
Tunnels, underground storage halls and other rock caverns are excavated in rounds. Drill holes are drilled at the tunnel face, and they are charged and blasted after the drilling. During one blast, an amount of rock material equal to the round is detached from the rock. A plan is drawn up in advance for excavating the rock cavern, and information is determined about rock types, among other things. Generally, the orderer of the rock cavern also sets various quality requirements on the cavern to be excavated. For each round, a drilling pattern is further designed as office work and delivered to the rock-drilling rig for drilling drill holes in the rock so as to generate the desired round.
Drilling pattern design programs that aid a designer in designing a pattern have been developed for designing the drilling pattern. Thus, the designing of a drilling pattern is an interactive operation between the designer and the drilling pattern design program. In present computer-aided drilling pattern design programs, the drilling pattern is designed at the navigation plane, i.e. the situation is examined from the point of view of the operator of the rock-drilling rig. Furthermore, rock blasting and rock detachment are three-dimensional events that are difficult to examine from the navigation plane. In addition, drilling patterns designed at the navigation plane have been found to contain significant inaccuracies particularly at the corners of the pattern, which results from the look-out angles of the profile holes of the pattern. Consequently, the problem in drilling patterns designed at the navigation plane is in that they do not achieve a sufficiently good accuracy in the blasting of a round.